The mechanisms involved in the generation of the pedal waves which drive pedal locomotion in Aplysia will be investigated. Work in this laboratory has established that these are generated in each pedal ganglion. The proposed research will: 1) Identify the pedal motor neurons whose activity constitutes the pedal wave motor program: This will be done using simultaneous intracellular recordings from pedal neurons, extracellular recordings from pedal nerves innervating a small portion of the foot, and transducer recordings to monitor pedal waves. 2) Analyze the pedal wave motor program: The firing sequence and phase relationships of the pedal wave motor neurons will be determined using intracellular recordings. 3) Determine the nature of the oscillator which generates the pedal wave motor program: This will be done by first examining the synaptic connections among pedal wave motor neurons and then examining synaptic connections between the pedal wave motor neurons and pedal interneurons whose activity is correlated with and can influence the pedal wave motor program.